1. Field of the Invention
The present invention relates to a data communication system, a data communication control method and an electronic apparatus, particularly to a network in which digitized image signals are dealt with.
2. Related Background Art
Recently, techniques for transmitting digitized animated image signals in real time have been developed. As one of the techniques, there is a high-rate serial bus (hereinafter referred to as 1394 serial bus) in conformity with IEEE (the Institute of Electrical and Electronics Engineers, Inc.) 1394-1995 standards (hereinafter referred to as IEEE 1394 standards). The technique is noted as a communication interface of a camera incorporating type digital video recorder (hereinafter referred to as DVCR) or another AV (Audio/Visual) apparatus.
In the IEEE 1394 standards, however, physical, electrical constitution of a connector, two types of most basic data transfer systems, and the like are merely defined, and it is not defined what type of apparatus is used and how the apparatus is constructed to be remote-controlled. Moreover, a type of data to be transmitted, a data format and a communication procedure for the transmittance are also indefinite.
Therefore, in the 1394 serial bus, a camera unit equipped in DVCR cannot be remote-operated, so that a user must directly operate a DVCR unit.
Furthermore, in the 1394 serial bus, a high-rate image transfer can be performed, but the setting of an image quality for a displayed image of a certain apparatus, or the setting of an image quality for a taken image of a certain apparatus cannot be remote-operated.
On the other hand, in the conventional DVCR, auto-focusing or another specific function is only preset for a fixed area on the taken image. Therefore, the user himself cannot set an arbitrary area for the taken image, or cannot select or set a desired function for the area. Furthermore, such operation cannot be performed in a remote manner.